Bantui dong kak….Sama caranya yang jelas ya ^_^

Np = 400 lilitan
Ns = 100 lilitan
Vp = 220 volt
Vs =?

Np/Ns = Vp/Vs
400/100 = 220/Vs
4 = 220/Vs
Vs = 220/4
Vs = 55 volt

jawaban A